He was born in Treorchy, Wales, and died in Hastings, East Sussex by suicide. He was a Flight Lieutenant and navigator in the Royal Air Force during World War 2, where he was involved in a plane crash that nearly resulted in his death. Despite this he reenlisted in 1951. Deeply committed to disarmament and haunted by the prospects of a nuclear war he fatally shot himself in the mouth in 1966.

His best-known novel, Red Alert was written while a serving RAF officer, (hence the original use of a pseudonym: Peter Bryant - the Bryan being taken from his middle name). Drawn from personal experience, Red Alert was the inspiration for Stanley Kubrick's classic film How I Learned to Stop Worrying and Love the Bomb.

Due to interest in nuclear themes sparked by Stanley Kramer's film version of On the Beach in 1959, the film rights to Red Alert were sold that year, only to be handed around until Stanley Kubrick bought them in 1962, reportedly for as little as $3,500.

Peter George co-wrote the screenplay for the film with Kubrick and Terry Southern, but wasn't completely satisfied with the overall satirical feel of the movie. After the film was released, he wrote a novelization of Dr. Strangelove and dedicated it to Kubrick.

George later wrote another novel to denounce the use of nuclear weapons, entitled Commander-1. He died in 1966 when he was working on his next novel, Nuclear Survivors.